Purging mechanism



v- 8, 1957 A. w. HART ETAL 3,354,608

PURGING MECHANI SM Filed Nov. 14, 1963 2 Sheets-Sheet 1 flEXA/YDE? M1914 660 66 u. Foss Afro? wa Nov. 28, 1967 A. w. HART ETAL,

PURGING MECHANISM H mm m WWW mm mm.

United States Patent 3,354,608 PURGING MECHANISM Alexander W. Hart and George J. Foss, Lancaster, Ohio,

assignors to Anchor Hocking Glass Corporation, Lancaster, Ohio, a corporation of Delaware Filed Nov. 14, 1963, Ser. No. 323,800 2 Claims. (Cl. 53-87) The present invention relates to the sealing art and more particularly to an air evacuating mechanism for removing air from containers prior to sealing the containers with a closure cap.

Containers are preferably sealed under conditions approximating a vacuum to avoid the deleterious effects of air on the packaged product. In order to do this, air is evacuated from a container and is replaced with either an inert gas or other fluid, depending on the product which is being packaged. For example, dry products, such as powdered coffee, generally use an inert gas to displace air from the headspace.

Immediately after the air is replaced, a closure cap is applied to the container to form a hermetically sealed package.

In the past it has been customary to combine in one machine the steps of purging air from the container headspace, replacing the air with an inert gas or other fluid, and sealing the container with a closure cap. Under the circumstances involved in packaging some food products, this arrangement has not been entirely satisfactory. In addition, the ability of such machines to remove atmospheric air for hermetically sealing containers has been impaired.

In the packaging of certain products, such as powdered coffee and the like, it has been found that when air is drawn out of the headspace, some of the powdered coffee tends to be drawn out with the air. In the past, an attempt has been made to prevent the product from being drawn out by putting a screen over the mouth of the container. However, the particular machines and screens which have been used have not produced satisfactory results with respect to providing a minimum loss of product and maximum air removal. Furthermore, the screens which have been used in the prior art tend to become clogged with the powdered product.

The present invention provides an improved air purging mechanism which will effectively purge air from the headspace of the container Without any loss in the contents thereof.

" Another object of the present invention is the provision of an improved screen for use in an air purging mechanism which will not clog.

Another object of the present invention is the provision of an improved mechanism for purging the air and substituting an inert gas therefor.

Another object of the present invention is the provision of an improved mechanism for purging air from the headspace of the container.

Another object of the present invention is the provision of a separate air purging unit which can be used on any sealing machine.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a diagrammatic top view showing the path of the containers as they pass from a gas purging unit to a sealing unit;

FIG. 2 is an enlarged top diagrammatic view of the air purging unit;

FIG. 3 is a sectional view taken along lines 33 of FIG. 2;

FIG. 4 is an enlarged sectional detail showing air being purged from a container;

FIG. 5 is an enlarged sectional detail showing an inert gas being substituted for the air which has been removed; and

FIG. 6 is a diagrammatic view similar to FIG. 2 showing another embodiment of the invention.

Referring to the drawings and more particularly to FIG. 1 thereof, the present invention comprises a gas purging unit 1 which is used in combination with a sealing unit 2. Air is removed from containers 3 and replaced with an inert gas in the air purging unit 1 and thereafter a closure cap 4 is applied to each container 3 in the sealing unit 2 to form a hermetically sealed package 5.

As shown in FIG. 1, the containers 3 are moved seriatim into the air purging unit 1. At this point air is removed from the headspace of the containers 3 and replaced with an inert gas and thereafter the container is moved into the separate sealing unit 2 which applies a closure cap 4 to the container to form a hermetically sealed package 5.

Referring to FIGS. 2 and 3, the separate air purging unit 1 comprises a stationary central spindle 8 and a sleeve bearing 6 upon which a container platform 9, a container spacing star wheel 10 having pockets 7 therein, and an air purging turntable 11 are mounted for rotation. The platform 9, the star wheel 10, and the turntable 11 are adapted to rotate about spindle 8 as a unit on bearing 6. Rotary power is supplied through sprocket 33 by a suitable conveyor chain (nOt shown).

A plurality of air purging elements 12 are mounted at the outer periphery of turntable 11 in overlying relation to the pockets 7 of star wheel 10. In the preferred embodiment, there are 24 air purging elements 12, spaced 15 degrees apart around the periphery of the turntable 11.

Each air purging element 12 comprises a purging head 13 for engaging the mouth of the container and an elongated support stem 14. A rubber-like sealing ring 15 lines the under surface of the head 13 to provide an air tight joint with the mouth of a container. A fine mesh screen 16 is located between the sealing ring 15 and the head 13. While any mesh screen material may be used, it has been found that good results have been obtained by using a screen having a rectangular mesh of about 20 lines per inch in one direction and about 250 lines per inch in the other direction. Satisfactory results have also been obtained by using a screen made of Rene 41 metal and stainless steel wire cloth. Such screens will prevent minute coffee particles from passing through when air is withdrawn from the container headspace and at the same time will not clog the screen and will permit air to pass.

Each purging element 12 is mounted by its stem 14 on turntable 11 by a slotted stationary sleeve 17 having a slotted bearing 18. A retainer ring 19 is superimposed over the bearing 18 and sleeve 17. A spring 20 sits between retainer ring 19 and a flange 21 on stem 14 to urge the stem 14 to a raised position.

Intermediate the ends of each stem 14 is a cam follower shaft 22 having a cam follower roller 24 mounted on the inner end thereof. When rotated, the cam follower roller engages a sector cam 25 mounted on a stationary web 35 and urges the purging element 12 downward so that the sealing ring 15 engages the mouth of the container, as illustrated in FIG. 3. When the cam roller 3 24 moves clear of the cam 25 the purging element 12 is returned to its upper position by means of the spring 20.

A manifold ring 26 is mounted between a stationary flange 36 and a ring 27 adapted to rotate with turntable 11. Set screws 37 hold the ring 26 and the flange 36 against relative rotation. A spring 40, fitted into recesses 38 and 39 in flange 36 and ring 26, respectively, urges the manifold ring 26 into positive contact with the rotating ring 27 at interface 30. The rotating ring 27 is mounted in an annular groove 23 near the inner periphery of the turntable and rotates with the turntable 11. The rotating ring 27 has a conduit 41 in communication with air space 42 in purging head 13 through fluid passage 28 in turntable 11, a. flexible hose 29, and conduit 43 in the purging head 13.

As shown in FIG. 2, the manifold ring 26 has a pair of arcuate slots 31 and 32 of varying length. The longer air evacuating slot 31 is connected to a vacuum pump (not shown) and the shorter fluid supplying slot 32 is connected to a source of fluid by means of a suitable conduit 34. Thus as turntable 11 rotates the purging conduit 41 is moved beneath the evacuating slot so that air is removed from the container and thereafter is moved beneath slot 32 so that an inert gas is deposited into the container. The slot 31 is longer than slot 32 so as to give the mechanism time for all the air to be removed.

In operation, a container is fed into the pocket 7 of star wheel 10 beneath the purging head 13. The purging head 13 is in its normally raised position. As rotation continues, cam follower roller 24 engages the cam 25 and the purging head is lowered to place the sealing ring 15 into sealing contact with the mouth of container 3. The conduit 41 then comes into communication with the longer air evacuating slot 31 in the manifold ring 26. In this position, air is withdrawn from the container 5, as shown in FIG..4, through the screen 16. As described above, the screen 16 prevents the escape of product from a container 3 during the evacuating operation.

When the evacuating operation is completed, the conduit 41 moves out of communication with slot 31 thus stopping the evacuation of air and comes into communication with slot 32 in the manifold ring 26, A fluid, such as inert gas, is introduced into the container through slot 32 as in FIG. 5 to fill the headspace. Since the screen has not been clogged by the previous evacuating operation, the inert gas will pass freely through the screen. Even though the screen has been slightly clogged with particles by the evacuation of the air, the inert gas will tend to force the particles back into the container. Through the entire operation, the cam roller 24 engages the cam 25 thereby keeping each sealing ring 15 of the purging head in sealing contact with the mouth of the container.

The purging head is then raised and this container is moved to the sealing unit 2. Since the inert gas is heavier than air it will stay in the container after the container leaves the purging unit 1 so that it will not be replaced 4 with air. In the sealing unit 2, a closure cap 4 is applied to each container 3 to form a hermetically sealed package 5.

In the embodiment shown in FIG. 6 the manifold is provided with a plurality of air evacuating slots 31a and a plurality of shorter fluid supplying slots 32a. In this manner, multiple cycling of the evacuating and fluid supplying operation may be achieved.

It is to be understood that although in the above description applicants invention has been described in connection with the use of an inert gas, other fluids may also be used to replace the air in the container without departing from the invention.

It will thus be seen that the present invention provides an improved air purging mechanism which is faster and more continuous which gives a better vacuum than other units in use and which will provide effective screen means of air.

As various changes may be made in the form, construe-- tion and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described the invention, it is claimed:

1. An air purging unit for removing air from the headspace of containers comprising a plurality of purging heads for said containers, a manifold comprising at least one evacuation means for evacuating air from each container, at least one injecting means adjacent said evacuating means for injecting a fluid into a container, means for moving said purging heads and said containers past said evacuating means to cause air to be evacuated therefrom through said purging heads and for moving said containers past said injecting means to cause a fluid to be injected into the container headspace through said purging heads, each of said purging heads having a stationary flat planar screen thereacross, a sealing element below said screen adapted to seal the container during said evacuation and injection, said screen having more lines in one direction than in the other direction to form slots, said container being subjected to said evacuating means for a longer continuous period of time than it is subjected to said injecting means.

2. An air purging unit as claimed in claim 1, wherein said screen has about 20 lines to the inch in one direction and about 250 lines to the inch in the other direction.

References Cited UNITED STATES PATENTS TRAVIS s. MCGEHEE, Primary Examiner. 

1. AN AIR PURGING UNIT FOR REMOVING AIR FROM THE HEADSPACE OF CONTAINERS COMPRISING A PLURALITY OF PURGING HEADS FOR SAID CONTAINERS, A MANIFOLD COMPRISING AT LEAST ONE EVACUATION MEANS FOR EVACUATING AIR FROM EACH CONTAINER, AT LEAST ONE INJECTING MEANS ADJACENT SAID EVACUATNG MEANS FOR INJECTING A FLUID INTO A CONTAINER, MEANS FOR MOVING SAID PURGING HEADS AND SAID CONTAINERS PAST SAID EVACUATING MEANS TO CAUSE AIR TO BE EVACUATED THEREFROM THROUGH SAID PURGING HEADS AND FOR MOVING SAID CONTAINERS PAST SAID INJECTING MEANS TO CAUSE A FLUID TO BE INJECTED INTO THE CONTAINER HEADSPACE THROUGH SAID PURGING HEADS, EACH OF SAID PURGING HEADS HAVING A STATIONARY FLAT PLANAR SCREEN THEREACROSS, A SEALING ELEMENT BELOW SAID SCREEN ADAPTED TO SEAL THE CONTAINER DURING SAID EVACUATION AND INJECTION, SAID SCREEN HAVING MORE LINES IN ONE DIRECTION THAN IN THE OTHER DIRECTION TO FORM SLOTS, SAID CONTAINER BEING SUBJECTED TO SAID EVACUATING MEANS FOR A LONGER CONTINUOUS PERIOD OF TIME THAN IT IS SUBJECTED TO SAID INJECTING MEANS. 